Detergent-dispersant additives for lubricating oils that are said to have a reduced tendency to cause foaming are described in U.S. Pat. No. 4,235,810 and European Patent Application Publication No. 1,318. Such additives are obtained by the coalkylation of an aromatic hydrocarbon, such as benzene, toluene, or orthoxylene, with a mixture of 5-95% (preferably 95-70%) by weight of a branched C.sub.15 -C.sub.40 olefin and 95-5% (preferably 30-5%) by weight of a linear C.sub.16 -C.sub.30 olefin, followed by sulfonation of the coalkylate and neutralization of the resultant sulfonic acid with an alkaline earth base.